The key to protecting wetlands is knowing how they're being lost

Posted: Saturday, June 01, 2002

For some wetlands are wildlife magnets whose trees, grasses and waters are teeming with all manner of wondrous creatures. To others, they're soggy nuisances -- mosquito-breeding grounds that get in the way of farming and development.

But, for the environment, swamps and marshes play a far more technical role -- mainly filtering our water of impurities and regulating flooding by allowing overflow to slowly drain back into nearby waterways.

Despite their vital purpose, wetlands are a disappearing feature in the United States. According to a recent Associated Press article, it was estimated that by 1980 half of the nation's wetlands had been destroyed by agriculture, urbanization and timber harvesting.

Of the 50.7 million acres of forested wetlands remaining in the United States, 32 million acres are located in the South. These Southern wetlands remain under significant development pressure. From 1986 to 1997, roughly 3.5 million acres of Southern wetlands were clearcut or otherwise altered, and 350,000 acres were destroyed, according to the AP report.

A study of northern Georgia, including Clarke and Oconee counties, found that 20 percent of its wetlands were lost between 1974 and 1998. Twenty percent may not seem like a significant amount until you consider wetlands account for only 1 percent of the total acreage in the counties of northern Georgia.

The information about wetland loss was compiled by the Georgia Land Use Trends project, begun three years ago through a $1-million grant from the Turner Foundation and through funding from the National Science Foundation and other agencies. The project employed satellite images to track changes over the years in land use over all of Georgia. The satellite tracking, enhanced by aerial photography and other data were used to create detailed maps showing the land-use changes.

The 1998 series of maps can be viewed via the Internet from a page at the University of Georgia's Institute of Ecology's Web site (http://narsal.ecology.uga.edu). In the near future researchers intend to make the 1974 series and 1985 series of maps available on the Internet. Later maps from the 1990s and 2001 will be added.

For most people it came as no surprise that the maps show suburban zones -- an indication of sprawl -- spread out from the major cities and more than doubled statewide from 1974 to 1999. It's obvious that metro areas such as Athens, Atlanta and Augusta are developing large portions of land as sprawl spreads out toward surrounding counties.

What did surprise researchers was the magnitude of wetlands loss in the northern part of the state. Now, experts are trying to come with answers about why the losses were so great.

Researchers said they will try to get more grant funding so they can create more maps of future land-use changes in coming years, do more analysis of the trends revealed by the maps and build a comprehensive, publicly accessible database so residents can do their own data analyses of the changes in their own neighborhoods.

The Georgia Land Trends Project, headed up by two University of Georgia faculty members, can continue to serve as an invaluable resource for planners, government officials, citizens and others. Knowing where growth is occurring and any problems which might result from that growth can help in mapping out the future of Georgia's counties.

Sprawl and wetlands loss are two challenges the project's maps helped define. Now it's up to our leaders to use the information in helping address those issues and in planning to avoid repeating mistakes of the past.